+ def setup_peripherals(self, m):
+ comb, sync = m.d.comb, m.d.sync
+
+ # okaaaay so the debug module must be in coresync clock domain
+ # but NOT its reset signal. to cope with this, set every single
+ # submodule explicitly in coresync domain, debug and JTAG
+ # in their own one but using *external* reset.
+ csd = DomainRenamer(self.core_domain)
+ dbd = DomainRenamer(self.dbg_domain)
+
+ m.submodules.core = core = csd(self.core)
+ # this _so_ needs sorting out. ICache is added down inside
+ # LoadStore1 and is already a submodule of LoadStore1
+ if not isinstance(self.imem, ICache):
+ m.submodules.imem = imem = csd(self.imem)
+ m.submodules.dbg = dbg = dbd(self.dbg)
+ if self.jtag_en:
+ m.submodules.jtag = jtag = dbd(self.jtag)
+ # TODO: UART2GDB mux, here, from external pin
+ # see https://bugs.libre-soc.org/show_bug.cgi?id=499
+ sync += dbg.dmi.connect_to(jtag.dmi)
+
+ cur_state = self.cur_state
+
+ # 4x 4k SRAM blocks. these simply "exist", they get routed in litex
+ if self.sram4x4k:
+ for i, sram in enumerate(self.sram4k):
+ m.submodules["sram4k_%d" % i] = csd(sram)
+ comb += sram.enable.eq(self.wb_sram_en)
+
+ # XICS interrupt handler
+ if self.xics:
+ m.submodules.xics_icp = icp = csd(self.xics_icp)
+ m.submodules.xics_ics = ics = csd(self.xics_ics)
+ comb += icp.ics_i.eq(ics.icp_o) # connect ICS to ICP
+ sync += cur_state.eint.eq(icp.core_irq_o) # connect ICP to core
+
+ # GPIO test peripheral
+ if self.gpio:
+ m.submodules.simple_gpio = simple_gpio = csd(self.simple_gpio)
+
+ # connect one GPIO output to ICS bit 15 (like in microwatt soc.vhdl)
+ # XXX causes litex ECP5 test to get wrong idea about input and output
+ # (but works with verilator sim *sigh*)
+ # if self.gpio and self.xics:
+ # comb += self.int_level_i[15].eq(simple_gpio.gpio_o[0])
+
+ # instruction decoder
+ pdecode = create_pdecode()
+ m.submodules.dec2 = pdecode2 = csd(self.pdecode2)
+ if self.svp64_en:
+ m.submodules.svp64 = svp64 = csd(self.svp64)
+
+ # convenience
+ dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
+ intrf = self.core.regs.rf['int']
+
+ # clock delay power-on reset
+ cd_por = ClockDomain(reset_less=True)
+ cd_sync = ClockDomain()
+ m.domains += cd_por, cd_sync
+ core_sync = ClockDomain(self.core_domain)
+ if self.core_domain != "sync":
+ m.domains += core_sync
+ if self.dbg_domain != "sync":
+ dbg_sync = ClockDomain(self.dbg_domain)
+ m.domains += dbg_sync
+
+ ti_rst = Signal(reset_less=True)
+ delay = Signal(range(4), reset=3)
+ with m.If(delay != 0):
+ m.d.por += delay.eq(delay - 1)
+ comb += cd_por.clk.eq(ClockSignal())
+
+ # power-on reset delay
+ core_rst = ResetSignal(self.core_domain)
+ if self.core_domain != "sync":
+ comb += ti_rst.eq(delay != 0 | dbg.core_rst_o | ResetSignal())
+ comb += core_rst.eq(ti_rst)
+ else:
+ with m.If(delay != 0 | dbg.core_rst_o):
+ comb += core_rst.eq(1)
+
+ # connect external reset signal to DMI Reset
+ if self.dbg_domain != "sync":
+ dbg_rst = ResetSignal(self.dbg_domain)
+ comb += dbg_rst.eq(self.dbg_rst_i)
+
+ # busy/halted signals from core
+ core_busy_o = ~core.p.o_ready | core.n.o_data.busy_o # core is busy
+ comb += self.busy_o.eq(core_busy_o)
+ comb += pdecode2.dec.bigendian.eq(self.core_bigendian_i)
+
+ # temporary hack: says "go" immediately for both address gen and ST
+ l0 = core.l0
+ ldst = core.fus.fus['ldst0']
+ st_go_edge = rising_edge(m, ldst.st.rel_o)
+ # link addr-go direct to rel
+ m.d.comb += ldst.ad.go_i.eq(ldst.ad.rel_o)
+ m.d.comb += ldst.st.go_i.eq(st_go_edge) # link store-go to rising rel
+
+ def do_dmi(self, m, dbg):
+ """deals with DMI debug requests
+
+ currently only provides read requests for the INT regfile, CR and XER
+ it will later also deal with *writing* to these regfiles.
+ """
+ comb = m.d.comb
+ sync = m.d.sync
+ dmi, d_reg, d_cr, d_xer, = dbg.dmi, dbg.d_gpr, dbg.d_cr, dbg.d_xer
+ intrf = self.core.regs.rf['int']
+
+ with m.If(d_reg.req): # request for regfile access being made
+ # TODO: error-check this
+ # XXX should this be combinatorial? sync better?
+ if intrf.unary:
+ comb += self.int_r.ren.eq(1 << d_reg.addr)
+ else:
+ comb += self.int_r.addr.eq(d_reg.addr)
+ comb += self.int_r.ren.eq(1)
+ d_reg_delay = Signal()
+ sync += d_reg_delay.eq(d_reg.req)
+ with m.If(d_reg_delay):
+ # data arrives one clock later
+ comb += d_reg.data.eq(self.int_r.o_data)
+ comb += d_reg.ack.eq(1)
+
+ # sigh same thing for CR debug
+ with m.If(d_cr.req): # request for regfile access being made
+ comb += self.cr_r.ren.eq(0b11111111) # enable all
+ d_cr_delay = Signal()
+ sync += d_cr_delay.eq(d_cr.req)
+ with m.If(d_cr_delay):
+ # data arrives one clock later
+ comb += d_cr.data.eq(self.cr_r.o_data)
+ comb += d_cr.ack.eq(1)
+
+ # aaand XER...
+ with m.If(d_xer.req): # request for regfile access being made
+ comb += self.xer_r.ren.eq(0b111111) # enable all
+ d_xer_delay = Signal()
+ sync += d_xer_delay.eq(d_xer.req)
+ with m.If(d_xer_delay):
+ # data arrives one clock later
+ comb += d_xer.data.eq(self.xer_r.o_data)
+ comb += d_xer.ack.eq(1)
+
+ def tb_dec_fsm(self, m, spr_dec):
+ """tb_dec_fsm
+
+ this is a FSM for updating either dec or tb. it runs alternately
+ DEC, TB, DEC, TB. note that SPR pipeline could have written a new
+ value to DEC, however the regfile has "passthrough" on it so this
+ *should* be ok.
+
+ see v3.0B p1097-1099 for Timeer Resource and p1065 and p1076
+ """
+
+ comb, sync = m.d.comb, m.d.sync
+ fast_rf = self.core.regs.rf['fast']
+ fast_r_dectb = fast_rf.r_ports['issue'] # DEC/TB
+ fast_w_dectb = fast_rf.w_ports['issue'] # DEC/TB
+
+ with m.FSM() as fsm:
+
+ # initiates read of current DEC
+ with m.State("DEC_READ"):
+ comb += fast_r_dectb.addr.eq(FastRegs.DEC)
+ comb += fast_r_dectb.ren.eq(1)
+ m.next = "DEC_WRITE"
+
+ # waits for DEC read to arrive (1 cycle), updates with new value
+ with m.State("DEC_WRITE"):
+ new_dec = Signal(64)
+ # TODO: MSR.LPCR 32-bit decrement mode
+ comb += new_dec.eq(fast_r_dectb.o_data - 1)
+ comb += fast_w_dectb.addr.eq(FastRegs.DEC)
+ comb += fast_w_dectb.wen.eq(1)
+ comb += fast_w_dectb.i_data.eq(new_dec)
+ sync += spr_dec.eq(new_dec) # copy into cur_state for decoder
+ m.next = "TB_READ"
+
+ # initiates read of current TB
+ with m.State("TB_READ"):
+ comb += fast_r_dectb.addr.eq(FastRegs.TB)
+ comb += fast_r_dectb.ren.eq(1)
+ m.next = "TB_WRITE"
+
+ # waits for read TB to arrive, initiates write of current TB
+ with m.State("TB_WRITE"):
+ new_tb = Signal(64)
+ comb += new_tb.eq(fast_r_dectb.o_data + 1)
+ comb += fast_w_dectb.addr.eq(FastRegs.TB)
+ comb += fast_w_dectb.wen.eq(1)
+ comb += fast_w_dectb.i_data.eq(new_tb)
+ m.next = "DEC_READ"
+
+ return m
+
+ def elaborate(self, platform):
+ m = Module()
+ # convenience
+ comb, sync = m.d.comb, m.d.sync
+ cur_state = self.cur_state
+ pdecode2 = self.pdecode2
+ dbg = self.dbg
+
+ # set up peripherals and core
+ core_rst = self.core_rst
+ self.setup_peripherals(m)
+
+ # reset current state if core reset requested
+ with m.If(core_rst):
+ m.d.sync += self.cur_state.eq(0)
+
+ # check halted condition: requested PC to execute matches DMI stop addr
+ # and immediately stop. address of 0xffff_ffff_ffff_ffff can never
+ # match
+ halted = Signal()
+ comb += halted.eq(dbg.stop_addr_o == dbg.state.pc)
+ with m.If(halted):
+ comb += dbg.core_stopped_i.eq(1)
+ comb += dbg.terminate_i.eq(1)
+
+ # PC and instruction from I-Memory
+ comb += self.pc_o.eq(cur_state.pc)
+ self.pc_changed = Signal() # note write to PC
+ self.msr_changed = Signal() # note write to MSR
+ self.sv_changed = Signal() # note write to SVSTATE
+
+ # read state either from incoming override or from regfile
+ state = CoreState("get") # current state (MSR/PC/SVSTATE)
+ state_get(m, state.msr, core_rst, self.msr_i,
+ "msr", # read MSR
+ self.state_r_msr, StateRegs.MSR)
+ state_get(m, state.pc, core_rst, self.pc_i,
+ "pc", # read PC
+ self.state_r_pc, StateRegs.PC)
+ state_get(m, state.svstate, core_rst, self.svstate_i,
+ "svstate", # read SVSTATE
+ self.state_r_sv, StateRegs.SVSTATE)
+
+ # don't write pc every cycle
+ comb += self.state_w_pc.wen.eq(0)
+ comb += self.state_w_pc.i_data.eq(0)
+
+ # connect up debug state. note "combinatorially same" below,
+ # this is a bit naff, passing state over in the dbg class, but
+ # because it is combinatorial it achieves the desired goal
+ comb += dbg.state.eq(state)
+
+ # this bit doesn't have to be in the FSM: connect up to read
+ # regfiles on demand from DMI
+ self.do_dmi(m, dbg)
+
+ # DEC and TB inc/dec FSM. copy of DEC is put into CoreState,
+ # (which uses that in PowerDecoder2 to raise 0x900 exception)
+ self.tb_dec_fsm(m, cur_state.dec)
+
+ # while stopped, allow updating the MSR, PC and SVSTATE.
+ # these are mainly for debugging purposes (including DMI/JTAG)
+ with m.If(dbg.core_stopped_i):
+ with m.If(self.pc_i.ok):
+ comb += self.state_w_pc.wen.eq(1 << StateRegs.PC)
+ comb += self.state_w_pc.i_data.eq(self.pc_i.data)
+ sync += self.pc_changed.eq(1)
+ with m.If(self.msr_i.ok):
+ comb += self.state_w_msr.wen.eq(1 << StateRegs.MSR)
+ comb += self.state_w_msr.i_data.eq(self.msr_i.data)
+ sync += self.msr_changed.eq(1)
+ with m.If(self.svstate_i.ok | self.update_svstate):
+ with m.If(self.svstate_i.ok): # over-ride from external source
+ comb += self.new_svstate.eq(self.svstate_i.data)
+ comb += self.state_w_sv.wen.eq(1 << StateRegs.SVSTATE)
+ comb += self.state_w_sv.i_data.eq(self.new_svstate)
+ sync += self.sv_changed.eq(1)
+
+ return m
+
+ def __iter__(self):
+ yield from self.pc_i.ports()
+ yield from self.msr_i.ports()
+ yield self.pc_o
+ yield self.memerr_o
+ yield from self.core.ports()
+ yield from self.imem.ports()
+ yield self.core_bigendian_i
+ yield self.busy_o
+
+ def ports(self):
+ return list(self)
+
+ def external_ports(self):
+ ports = self.pc_i.ports()
+ ports = self.msr_i.ports()
+ ports += [self.pc_o, self.memerr_o, self.core_bigendian_i, self.busy_o,
+ ]
+
+ if self.jtag_en:
+ ports += list(self.jtag.external_ports())
+ else:
+ # don't add DMI if JTAG is enabled
+ ports += list(self.dbg.dmi.ports())
+
+ ports += list(self.imem.ibus.fields.values())
+ ports += list(self.core.l0.cmpi.wb_bus().fields.values())
+
+ if self.sram4x4k:
+ for sram in self.sram4k:
+ ports += list(sram.bus.fields.values())
+
+ if self.xics:
+ ports += list(self.xics_icp.bus.fields.values())
+ ports += list(self.xics_ics.bus.fields.values())
+ ports.append(self.int_level_i)
+
+ if self.gpio:
+ ports += list(self.simple_gpio.bus.fields.values())
+ ports.append(self.gpio_o)
+
+ return ports
+
+ def ports(self):
+ return list(self)
+
+
+
+# Fetch Finite State Machine.
+# WARNING: there are currently DriverConflicts but it's actually working.
+# TODO, here: everything that is global in nature, information from the
+# main TestIssuerInternal, needs to move to either ispec() or ospec().
+# not only that: TestIssuerInternal.imem can entirely move into here
+# because imem is only ever accessed inside the FetchFSM.
+class FetchFSM(ControlBase):
+ def __init__(self, allow_overlap, svp64_en, imem, core_rst,
+ pdecode2, cur_state,
+ dbg, core, svstate, nia, is_svp64_mode):
+ self.allow_overlap = allow_overlap
+ self.svp64_en = svp64_en
+ self.imem = imem
+ self.core_rst = core_rst
+ self.pdecode2 = pdecode2
+ self.cur_state = cur_state
+ self.dbg = dbg
+ self.core = core
+ self.svstate = svstate
+ self.nia = nia
+ self.is_svp64_mode = is_svp64_mode
+
+ # set up pipeline ControlBase and allocate i/o specs
+ # (unusual: normally done by the Pipeline API)
+ super().__init__(stage=self)
+ self.p.i_data, self.n.o_data = self.new_specs(None)
+ self.i, self.o = self.p.i_data, self.n.o_data
+
+ # next 3 functions are Stage API Compliance
+ def setup(self, m, i):
+ pass
+
+ def ispec(self):
+ return FetchInput()
+
+ def ospec(self):
+ return FetchOutput()
+
+ def elaborate(self, platform):